U.S. prosecutors have accused three men of conducting the largest ever theft of customer data from the giant JPMorgan Chase bank and other U.S. financial institutions.

In an indictment unsealed in New York Tuesday, the government charged two Israelis, Gery Shalon and Ziv Orenstein, and an American, Joshua Aaron, with computer hacking, wire fraud, illegal Internet gambling, securities fraud and other charges in a scheme that lasted from 2012 to a few months ago. The government said the men laundered their "vast criminal proceeds" through at least 75 shell companies.

The indictment accused the men of hacking into 12 companies, including two online brokerages, E*Trade Financial and Scottrade, and Dow Jones, the parent company of The Wall Street Journal.

"By any measure, the data breaches at these firms were breathtaking in scope and in size," U.S. Attorney Preet Bharara told reporters.

The indictment alleged the men stole the records of more than 83 million customers at Chase, the biggest bank in the U.S., from June to August a year ago. It said that one or more of the three men engaged in other criminal activity since 2007, including securities market manipulation and the operation of at least a dozen illegal Internet casinos.

Authorities said Shalon and Orenstein are being held in Israel, while Aaron has been living in Moscow and Tel Aviv and has not been arrested.